1. Field of the Invention
The present invention relates to scanning or tracking apparatus used for information processing, such as recording or reproduction of information on or from an information memory disk, such as an optical disk.
2. Description of the Related Art
Many information processing systems use an optical disk as an information memory medium. Compared with magnetic information processing systems which were previously used, disk processing systems have the following features or advantages:
The information memory capacity can be increased considerably, and stable information processing can be accomplished with less noise. During the information processing operation, moreover, there is no contact between the memory medium and the optical head, so that the possibility of damage is reduced. Because of these advantages, disk processing systems are widely used.
In one such information processing apparatus, the optical disk is rotated on a turntable and the optical head is moved in the radial direction of the disk while directed at a specified track of the disk. On the selected track, the optical head records or reproduces information on or from the disk. In order to prevent the optical head from being damaged by vibration during transportation, a lock mechanism is sometimes used. The lock mechanism is used to fix the head at a predetermined position during transportation. Also a brake mechanism may be used to shorten the step period of the turntable.
Conventionally, however, the lock and the brake are separate mechanisms. Therefore, the processing system must be provided with separate drive sources or components for these two mechanisms, so that it has a complicated construction, and entails high manufacturing costs. Furthermore, these mechanisms require substantial installation space, thus resulting in an increase in the size of the system.